Telephone cable splice case

ABSTRACT

This disclosure describes a splice closure for telephone cable pairs. The closure consists of a pair of plastic covers with metal lining or coating, and end plates of differing designs to accommodate from one to six cables. Internally, the closure includes a metallic harness at each end with outer and inner metal clamps placed around the cable and linked together with insulated metal tie bars. The closure is hermetically sealed at the faceplate-cover interface by a butyl rubber sealing compound. An air escape is included in the end plate to avoid air entrapment at the interface.

[451 Jan. 18,1972

United States Patent Baumgartner et al.

54] TELEPHONE CABLE SPLICE CASE 3,337,681 8/1967Smith.......................................174/92 [72] Inventors:Robert Garland Baumgartner, Baltimore; primary Examiner Dan-e|]LC|ayKenneth Chambers Madam Phoemx, Attorney-R. J. Guenther and Edwin B. Caveboth of Md.

[73] Assignec:

[57] ABSTRACT This disclosure describes a splice closure for tele pairs.The closure consists of a pair of plastic Bell Telephone Laboratories,Incorporated, Murray Hill, NJ.

Nov. 23, 1970 [21] App]. No: 91,843

phone cable 22 Filed: covers with 1 metal lining or coating, and endplates of differing designs to accommodate from one to six cables.lntemally, the closure includes a metallic harness at each end withouter and inner metal clamps placed around the cable and linked togetherwith insulated metal tie bars. The closure is hermetically sealed at thefaceplate-cover interface by a butyl rubber sealing compound. An airescape is included in the end plate to avoid air entrapment at theinterface.

[52] U.S. [5]] Int. Cl. [58] Field of Search 10 Claims, 9 DrawingFigures References Cited UNITED STATES PATENTS 10/1962 3,0ol,666 Duvallet PATENIED Jun 8 m2 SHEET 1 UF 4 R. G. BAUMGARTNER K C MACLEAN BYATTORNEY PATENTED JAN 1 8 I972 SHEET 2 BF 4 PATENTED JAN 1 8 1972 SHEET3 OF 4 FIG. 5

w I iiii m PATENTED JAN: 81872 SHEET l [1F 4 TELEPHONE CABLE SPLICE CASEFIELD OF THE INVENTION BACKGROUND OF THE INVENTION Although manytelephone closure designs are in existence, the conditions ofinstallation and working environment are so diverse and involved that noone closure concept to date has been adequate for all purposes.

Closures are used in the aerial, underground, and buried plant.Differing corrosion and stress factors occur in these environments.Closures wherever located are routinely reentered by splicers to effectnew or revised pair splices as the need arises. Present closure designsoften require extensive disassembly before splicing can commence.

Further, many cables have a gastight feature which must be maintained atthe closure. The integrity of the cable seals is increasingly crucial,especially with the prospect of higher frequencies to be transmittedover telephone pairs and the attendant tighter tolerances overparameters which are readily affected by changes in the cable interiormoisture content.

Accordingly, one object of the invention is to realize a telephone cableclosure with greater gastight integrity.

A further object of the invention is to simplify the installation andreentry of cable closures.

A further inventive object is to achieve a mechanically strong closurewhich is simple to install and reenter without compromising eithermechanical strength or gastight, water- Pursuant to the invention,mechanical strength is achieved by a harness assembly at each end of thesplice closure, which includes outer and inner metallic clamps placed onthe prepared ends of the cables to be joined, and linked together withinsulated metallic tie bars. The clamping means perform only a clampingfunction, the cable seals being provided by end plates to which theclamping assembly is attached, in conjunction with the closurestwo-piece outer shell or casing. Advantageously, these are moldedthermoplastic parts which, pursuant to one aspect of the invention, aredrawn together by metal inserts which are placed in receptacles moldedinto the plastic parts. The inserts in one embodiment are made ofsintered stainless steel and are characterized by a large flat bearingarea and a square boss. The height of the boss may be chosen so thatwith the capscrew inserted and torqued, the entire assembly can be setto come together with a controlled amount of tension on the capscrew,which then acts as a spring to permanently lock together the plasticmembers embraced between them. Advantageously, however, any insert maybe replaced in the field.

In the end plates, corrugations are used in the cable sear area which,pursuant to a further facet of the invention, include air escapecorridors. During the closure assembly, as the end plate sections arebrought together, the corridors allow air to escape as the sealant iscompressed. This avoids trapping air at the'interface with its attendantreduction of adhesive surface. i

The invention and its further objects, features, and advantages will bemore readily apprehended from a reading of the detailed description tofollow of an illustrative embodiment.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a frontal perspective view inpartial cutaway 'of the cable closure;

FIG. 2 is a side sectional view of locking means for the cable covers;

FIG. 3 is an exploded side perspective view of a closure end plate andclamp;

FIG. 4 is an exploded side perspective view of a second embodiment ofend plate;

FIG. 5 is a sectional side view of fasteners for the closure;

FIG. 6 is a side perspective view of one-half of an end plate;

FIG. 7 is a front partial perspective diagram showing the closure coversjoined;

FIG. 8 is a sectional side detail view showing the joining of two endplate sections; and

FIG. 9 is a frontal perspective view of the midsection of a second endplate embodiment.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT FIG. 1 shows aclosure constructed according to the present invention and consisting ofa two-piece outer cover designated 1 comprising a top shell 2 and abottom shell 3. The shells 2, 3 are each semicylindrical in overallshape, and each has longitudinal, outwardly extending edge flanges 4a,4b on either side. Each flange 4a, 4b has an upturned edge 5.

A number of spaced parallel ribs 6, 7 run longitudinally on the skin oftop shell 2 and of bottom shell 3. Also a plurality of spaced transverseribs are formed in the top and bottom shells 2, 3. The ribs 6, 7constitute a honeycomblike reenforcing structure for the outer cover. Aweb 8 joins each transverse rib 6 with the flanges 4a, 4b at the edge 5as seen in FIG. 2, further rigidifying the flanges.

Along each flange 4a, 4b, interspersed along the flange at intervals anumber of square passages 9 are provided between adjacent webs. As seenin FIG. 2, the passages 9 in flange 4b, for example, accept an insert 10having an unthreaded chamber; while the passages in flange 4a accept aninsert 11 with a threaded chamber. The inserts 10, 11 advantageouslyhave square bosses 12, such as seen in FIG. 7. FIG. 5 shows a tab 13formed on the surface of flange 4a and 4b and having a lip 14, serves tosnap-mount and retain the respective inserts 10, II. Advantageously, theinserts 10, 11 are placed in position during the factory assembly byforcing them past the lip 14. This approach avoids having to press-fitthe inserts which risk distorting the covers; or molding the inserts inplace, in which case replacement in the field is difficult if the needshould arise. Advantageously, the inserts are made of sintered stainlesssteel. The height of the square boss 12, pursuant to the invention, canbe selected so that with the capscrew 15 inserted and sufficientlytorqued, the top and bottom shells 2, 3 come together with bossescontacting, to provide a controlled amount of tension on the capscrew15. This, then, acts as a spring with which the plastic shells 2, 3 arelocked in position. Even if they cold-flow, the shells cannot cause thespring tension to decrease. Further, if the capscrew 15 shouldcrossthread or gall in the insert, the insert can readily be replaced bymoving the lip 14 back far enough to enable the insert to be removed.

As seen in FIG. 7, the interior of the top and bottom shells 2, 3comprise a generally cylindrical enclosure. The interface between theshells 2, 3 is formed as in FIG. 2 to provide a chamber 16 which, priorto assembly, is filled with sealant. A shielding layer 17 of suitablematerial such as aluminum foil is secured to the interior side of shells2, 3 respectively, in the re gion between two spaced, inwardly extendinginterior ribs 18a, 18b fonned respectively in the top and bottom shells2, 3. Alternatively, by suitable electroplating methods of metallicplating such as copper may be placed on desired portions of the interiorsurface of the shells 2, 3 as well as the end plates to be described.One method calls for an electroless deposition of a nickel substratefirst, which acts as a primer for later electrolytic deposition ofcopper. At the edge of each shell 2, 3, a second spaced rib set 19a, 19bis formed. The chamber thus defined between the two-rib sets 18a, 18band 19a, 19b, which are designated 20, serves to receive a sealant.

SINGLE-CABLE END PLATE STRUCTURE A structure for gripping a single cableand for mounting same within the outer cover 1 is shown in FIG. 3. Theend plate includes a right shell 22 shown in FIG. 3, and an identicalleft shell 23 shown in FIG. 6. The shell 22 consists of a body 24supporting a rim 25 bounded by a pair of annular outer ribs 26a and 27a.Similarly, the left shell 23 includes a body portion 24 supporting a rim25 bounded by annular ribs 26b, 27b as seen in FIG. 6.

Inwardly of body 24 on each of the shells 22, 23 is a sernicylindricalflange section 28, 29 respectively. The flange 29 of shell 23 isbracketed to the body 24 by the mounting flange 30a, 30b. Similarly, thesernicylindrical flange 28 is bracketed to body 24 of right shell 22 bythe mounting flanges 31a, 31b, seen partially in FIG. 3.

The flanges 30a, 30b, 31a, 31b, each has a square orifice 32 as seen inFIGS. 3 and 6. Adjacent to each orifice 32, on its exterior side, is aridge 33 such as seen in FIG. 3. Threaded inserts 34, and unthreadedinserts such as 35 are placed in matching pairs in the orifices 32 and athreaded fastener 36 is used to draw down the opposing inserts 34, 35.

Along the interior surface 37 of flange 28, there are provided a numberof arcuate parallel'ridges 38, best seen in FIG. 6 in conjunction withthe left shell 23. The ends 38a of each ridge 38 stop short of theflange surface 30b. Between the two legs of flange 30a, and of flange30b as well, is provided a depressed surface 39 bounded in each case bya pair of grooves 40. The latter extend as seen in FIG. 6, inwardlytoward the ridges 38. When the right and left shells 2'2, 23 are joinedas seen in FIG. 8, the surface 39 and associated grooves 40 form asealing compound chamber.

Midway atop the sernicylindrical flanges 28, 29, as illustrated in FIG.3, a U-shaped saddle 41 is fastened. There thus are two saddles 41 foreach single cable end plate 21, spaced 180 apart along the flanges 28,29. The saddles 41 each receive a U-shaped tie bar 42 which fastens tothe saddle as with bolt 42a. Either end of the two tie bars 42 thus isconnected to a saddle 41 which, pursuant to the invention, affords astrong mechanical linking between the two end plates of the closure.lnwardly of its ends, each tie bar 42 is fully insulated with a jacket43 as shown in FIG. 3.

Attaching across tie bars 42 is an outer cable clamp 45 consisting of atop member 46 and a bottom member 47. Each member 46, 47 includes acorrugated semicircular interior surface 48, which engages the outercable jacket such as 49 in FIG. 4 with its corrugations.

The members 46, 47 are identically shaped. A first end 50 of each memberincludes a pair of spaced outwardly extending arms 51, the upper armjoining to a flat surface 52 through the tapered surface 53. A secondend of 54 includes a flat 55, and outwardly thereof a tapered surface56. The two cable clamp members 46, 47 are brought together by threadedfastener such as 57 through an unthreaded hole 59 in end 50 and engaginga threaded hole 58 in end 54. An inner sheath clamp 104a shown in FIG. 4is contacted by the corrugations of surface 48. In a similar suchexpedient thecable clamp arms at the other end are joined. The clampwhen assembled is attached to the tie bar 42 by engagement of the spacedarms 51 at either end around the tie bar and fastening of the assemblythereto by, for example, the threaded hex head capscrew 57a.

GAS PRESSURE INLET For multipair cables which are internallypressurized, it is necessary to afford a gas pressure inlet to theassembled housing of the present invention. To this end, a threadedorifice 110 is provided as a molded-in-place insert in the end platehalf as shown in FIG. 3. Normally, orifice 110 is used as a gas pressureinlet and is fitted with an external pipe plug only. It can also provideexternal ground and in this use it accommodates the threaded end 112 ofa lug 111. A strap 113 is fastened to the other end 114 of lug 111 aswith nut 115; and

the second end of the strap then is fastened as with bolt 116 to clamp45 and the threaded hole 117 therein. The system thus affords anelectrical grounding path from the cable clamp 45 to the exterior of theclosure. The path is completed by inserting a second two-ended lug 118from the exterior side of orifice 110 thus to contact lug 111. Agrounding bar 119 then is attached to the other end of lug 118 as with abolt nut 120. The grounding bar 119 in turn may be attached to anysuitable exterior ground.

DOUBLE-CABLE END PLATE As seen in FIG. 4 a double-cable end plate 65 canbe used in place of the single-cable end plate of FIG. 3 on either orboth closure ends. End plate 66 comprises an upper crescent 67 and alower crescent 68 in between which is a midsection 69. The exteriorsurfaces of the elements 67, 68, 69, form a cylindrical rim 70 boundedby annular outer ribs 71, 72, in the same fashion as obtains for asingle-cable end plate 21. The upper and lower crescents 67, 68 eachincludes a semicylindrical flange 73a, 73b respectively. These serve thesame function as flanges 28, 29 of the single-cable end plate of FIG. 3.The interior sernicylindrical surfaces of upper and lower crescents 67,68 comprise the same ribbed construction with arcuate ridges 78 as hasbeen described with respect to FIG. 6.

Midsection 69, shown in FIG. 9, includes two semicylindrical interiorsurfaces 74. Each surface 74 terminates at a pair of mounting flanges75, 76. The rim 70 surface is joined with a depressed surface 77 whichbisects the flanges 75, 76. Along the sernicylindrical interior surfaces74 a plurality of arcuate ridges 78 are formed, which advantageously aresubstantially equivalent to the ridges 38 explained earlier with respectto FIG. 6.

Midsection 69 also includes a pair of tie-bar saddles 83 fastened onopposite central portions of the interior side.

A square passage 79 is placed at the end of each of the flanges 75, 76,to accommodate square threaded and unthreaded inserts 80, 81 such asshown in FIG. 4. To aid in retaining each of the inserts 80, 81, a lip82 is provided adjacent each square hole.

A two-cable clamp designated 84 is shown in exploded perspective view inFIG. 4. Outer clamp 84 consists of a top half 85, a bottom half 86 and acenter section 87. Top and bottom halves 85, 86 include asemicylindrical and corrugated interior surface 88 within flanges 89,90. Center section 87 includes two oppositely facing sernicylindricalsurfaces 91, 92 each also corrugated. The surfaces 91, 92 are reenforcedby a pair of walls 93, 94. At the center point in each wall 93, 94, anotch 95 with a threaded passage is provided to receive and secure thetie bars 96 as with capscrew 97. A second fastening is made between thetie bar 96 and the saddles 83 as with capscrew 98. An inner sheath clamp104a shown in FIG. 4 is placed on cable 100 for contacting metallicsheath 104. Tabs 104b then afford electrical contact to the clampmetallic top half 85.

The semicircular interior flange 28 as shown in FIG. 6 is bounded bycircular flanges 29. The surfaces of the latter are above the topportions of the ridges 38. Similarly, the interior cylindrical surfacesof the upper and lower crescents 67, 68 as well as the twosernicylindrical flanges 73a, 73b of the midsection 69 of end plate type66 are also bounded by semicircular wall portions, such as the flange29. For the midsection 69, shown in FIG. 9, the wall portion isdesignated 74a.

METHOD OF ASSEMBLY A cable 100 such as shown in FIG. 4 is prepared forconnection to a two-cable splice closure of the present invention firstby building up of a layer approximately l k inches wide of a suitablesealing compound such as butyl rubber between a pair of washers (notshown) placed on the cable in conventional fashion. Then the lowercrescent 68 of double-cable end plate 66 is placed over the washers, thewall portions 74a fully enveloping the two washers. Next, an amount ofsealing compound is placed in the depressed surfaces 77, and the endplate midsection 69 is placed over the washers, the washers beingembraced inwardly of the wall portions 74a. In a similar fashion, asecond cable 101 is prepared and placed between the secondsemicylindrical surface of midsection 69 and upper crescent 67. When thecable 100 is in place, the upper crescent 67 is tightened down upon themidsection 69 and similarly when cable 101 is in place, the lowercrescent 68 is tightened.

It is inevitable thatin applying the faceplate elements to the cablejacket a certain amount of air be trapped beneath the sealing compound.This air should be expelled to achieve the maximum possible adhesion tothe end plate surfaces. Pursuant to the invention, the trapped air lyingbeneath the sealing compound escapes in paths between the ridges 78. Theair then bleeds along the path between the ridge ends 78a and thegrooves 40a and thence on through the grooves.

After the first end plate is assembled, the second end plate for theother end of the closure is then assembled in like fashion. The secondend plate can be either a singleor a double-cable type. Thereafter, tiebars such as 96 are placed in position in the manner described. Theouter clamps such as clamp 45 for the single-cable end plate and clamp84 for the double-cable end plate, are placed into contact with thecable jacket 103 and also the sheath 104 through the inner clamp 104aand its tabs 104b. Inner clamp 104a is inserted over the sheath 104 inconventional fashion. Telephone cable pairs then are spliced together inconventional fashion; and thereafter all splices are protected with oneor two outer wraps and electrical shielding.

Next, a ribbon 106 of sealing compound is placed in the rim of the endplate, such as in rim 25 of FIG. 3. The bottom shell 3 is placed underthe end plates, the latter being embraced between the ribs 18a, 19a and18b, 1% shown in FIG. 7, A length of sealing cord then is placed in theindentation of bottom shell 3 that defines half of the sealant chamber16 as shown in FIG. 2, at and along both sides of the bottom shell.Chamber 16 is seen to join the volume within the last-named ribs.Finally, the top shell 2 is placed over the bottom shell 3 and capscrewsare inserted and tightened into the inserts 10, 11.

It is seen that this assembly provides sealant chambers between the topand bottom shells 2, 3 and also along the entire periphery of the endplates where these join the top and bottom shells 2, 3.

It is to be understood that the embodiments described herein are merelyillustrative of the principles of the invention. Various modificationsmay be made thereto by persons skilled in the art without departing fromthe spirit and scope of the invention. 1

What is claimed is:

I. A closure for composite, sheathed multipair telephone cablecomprising:

an outer plastic cover comprising top andbottom mating shells, each withsemicylindrical interior surfaces and a pair of spaced arcuate ribsformed at said surface ends, said shells having mating flanges extendingoutwardly along either side and having upturned edges, said flangeshaving matching grooves defining a closed chamber, bonding sealant insaid chamber, plural longitudinal and plural circular transverse ribsformed on the outer surface of each said shell, each said transverse ribincluding an end web joining said flange upturned edge;

first and second circular-rimmed end plates closely fitting between therespective said spaced arcuate ribs, bonding sealant between said rimand said arcuate ribs, each said end plate comprising means forenveloping said cable jacket;

first and second cable-gripping means inwardly of the respective saidend plates; and

tie bar means for mechanically connecting said gripping means and formounting said end plates.

2. A closure pursuant to claim 1, wherein each said end plate furthercomprises a pair of annular outer ribs at the edge of said outer rimsaid ribs mounting in respective contacting relation between said spacedarcuate ribs of said mating shell.

3. A closure pursuant to claim 2, wherein each said end plate furthercomprises two or more dissemblable sections, and wherein saidjacket-enveloping means comprises one or more pairs of semicylindricalsurfaces each said surface comprising raised end walls and pluralannular spaced ribs of lesser height than said end walls, each of saidsurfaces terminating in two mounting flanges each with a depressedmidregion, defined between a pair of spaced notches placed widthwiseacross each said flange, the notch interior ends being closely adjacentsaid rib ends, and the notch exterior ends extending to the end platerim surface.

4. A closure pursuant to claim 2, wherein each said end plate furthercomprises a pair of oppositely mounted saddles for receiving said tiebar means, and wherein the latter comprises U-shaped metallic rods withfull insulative cover therearound except at their end portions, andmeans connecting each said end portion to a respective said end platesaddle.

5. A closure pursuant to claim 2, wherein said gripping means comprisestwo or more metallic clamps each having at least one semicylindricalcorrugated interior surface, means for effecting electrical andmechanical contact between said surfaces and said cable sheath, meansfor fastening said clamps together, said clamps further comprising twoopen U shaped slots for snug engaging and securing to said tie bar.

6. A closure pursuant to claim 2, further comprising means for joiningsaid shells comprising plural square holes with bossed threaded andunthreaded inserts therein, one said hole located between each said web,said inserts slightly spaced apart when said flanges are in contact,said shells being drawn together by said bosses with a controlled forceuntil said bosses contact.

7. A closure pursuant to claim 6 further comprising a metallic foillayer disposed on said shell interior surfaces between the twoinwardmost said arcuate ribs, said foil serving as a shield fortelephone conductors in said cable.

8. A closure pursuant to claim 7, further comprising tab means extendingupwardly adjacent each said flange hole, said tab means firmly engagingone side of each associated said insert and fixing same in said hole.

9. A closure pursuant to claim 8 further comprising separate gastightgrounding means connected to each said sheath gripping means, andleading through said end plate for connection externally to a ground.

10. A closure comprising: first and second semicylindrical plasticcovers each having interior metallic lining, longitudinal joiningflanges, and recessed end wells, end glands chambered in said end wellsand comprising one or more axial circular entrances for passing cable,each entrance including circular rib means for trapping sealing compoundand transverse airbleeder corridors, each gland having two or moreflanged sections, sintered stainless steel boss means embedded in eachsaid section, means for adjusting the height of each said boss, andscrew means for bringing together said bosses.

1. A closure for composite, sheathed multipair telephone cablecomprising: an outer plastic cover comprising top and bottom matingshells, each with semicylindrical interior surfaces and a pair of spacedarcuate ribs formed at said surface ends, said shells having matingflanges extending outwardly along either side and having upturned edges,said flanges having matching grooves defining a closed chamber, bondingsealant in said chamber, plural longitudinal and plural circulartransverse ribs formed on the outer surface of each said shell, eachsaid transverse rib including an end web joining said flange upturnededge; first and second circular-rimmed end plates closely fittingbetween the respective said spaced arcuate ribs, bonding sealant betweensaid rim and said arcuate ribs, each said end plate comprising means forenveloping said cable jacket; first and second cable-gripping meansinwardly of the respective said end plates; and tie bar means formechanically connecting said gripping means and for mounting said endplates.
 2. A closure pursuant to claim 1, wherein each said end platefurther comprises a pair of annular outer ribs at the edge of said outerrim said ribs mounting in respective contacting relation between saidspaced arcuate ribs of said mating shell.
 3. A closure pursuant to claim2, wherein each said end plate further comprises two or moredissemblable sections, and wherein said jacket-enveloping meanscomprises one or more pairs of semicylindrical surfaces each saidsurface comprising raised end walls and plural annular spaced ribs oflesser height than said end walls, each of said surfaces terminating intwo mounting flanges each with a depressed midregion, defined between apair of spaced notches placed widthwise across each said flange, thenotch interior ends being closely adjacent said rib ends, and the notchexterior ends extending to the end plate rim surface.
 4. A closurepursuant to claim 2, wherein each said end plate further comprises apair of oppositely mounted saddles for receiving said tie bar means, andwherein the latter comprises U-shaped metallic rods with full insulativecover therearound except at their end portions, and means connectingeach said end portion to a respective said end plate saddle.
 5. Aclosure pursuant to claim 2, wherein said gripping means comprises twoor more metallic clamps each having at least one semicylindricalcorrugated interior surface, means for effecting electrical andmechanical contact between said surfaces and said cable sheath, meansfor fastening said clamps together, said clamps further comprising twoopen U-shaped slots for snug engaging and securing to said tie bar.
 6. Aclosure pursuant to claim 2, further comprising means for joining saidshells comprising plural square holes with bossed threaded andunthreaded inserts therein, one said hole located between each said web,said inserts slightly spaced apart when said flanges are in contact,said shells being drawn together by said bosses with a controlled forceuntil said bosses contact.
 7. A closure pursuant to claim 6 furthercomprising a metallic foil layer disposed on said shell interiorsurfaces between the two inwardmost said arcuate ribs, said foil servingas a shield for telephone conductors in said cable.
 8. A closurepursuant to claim 7, further comprising tab means extending upwardlyadjacent each said flange hole, said tab means firmly engaging one sideof each associated said insert and fixing same in said hole.
 9. Aclosure pursuant to claim 8 further comprising separate gastightgrounding means connected to each said sheath gripping means, andleading through said end plate for connection externally to a ground.10. A closure comprising: first and second semicylindrical plasticcovers each having interior metallic lining, longitudinal joiningflanges, and recessed end wells, end glands chambered in said end wellsand comprising oNe or more axial circular entrances for passing cable,each entrance including circular rib means for trapping sealing compoundand transverse air-bleeder corridors, each gland having two or moreflanged sections, sintered stainless steel boss means embedded in eachsaid section, means for adjusting the height of each said boss, andscrew means for bringing together said bosses.